# break 和continue
# break 是跳出循环
# 而continue 是结束本次循环
sum=0
flag=True
for i in range(1,6):
    grade=int(input("输入第"+str(i)+"名的成绩："))
    if int(grade)<0:
        flag=False
        break;
    sum=sum+grade
if flag:
    avg=sum/5
    print(avg)





people=0
for i in range(1,6):
    grade=int(input("输入第"+str(i)+"名的成绩："))
    if int(grade)<80:
        continue
    people=people+1
print(str(people)+":"+"5")

sum=0
flag=True
for i in range(1,6):
    grade=int(input("输入第"+str(i)+"名的成绩："))
    if int(grade)<0:
        flag=False
        break;
    elif  int(grade)>80:
        sum=sum+1
if flag:
    print(str(sum)+":"+"5")